Method oe making bottle closures



May 26, 1931. v c. E. McMANus 1,805,880

.METHOD OF MAKING-BOTTLE CLQSURES Filgd June 27, 1925 Patentedv May 26,1931 UNITED STATES PATENT OFFICE l CHARLES MCMANUS, OF NEW YORK, N. Y.,ASSIGNOR T ROWN CORK & SEAL COM- PANY, INC.,v 0F NEW YORK, N. Y., A.COR'TPORATION OF NEW YORKv METHOD 0F MAKING `.BO'lI'LE CLOSURESlApplication led .Tune 27, 1925. 'Serial No. 40,126.

My-,invention relates to the method of making bottle closures, and moreparticularly bottle closures of the crown tvpe in which the. cushiondisk is formed of composition cork..

Composition cork is formed of granules of natural cork cemented togetherby a very thin coating of a suitable adhesive.

as Waste cork or refuse cork resulting from the production of Stoppersand other articles of natural cork.

The uses to which composition cork is put have increased in recentyears, and the nat-j sition cork is not suliicient to meet demands forthis waste at the present time, and under present manufacturingconditions.

f \In the .production of composition cork, it

is customary to use fairly large cork granules mixed With finergranules, the harder, particles of the cork, from toward the outersurface of the cork Wood, being separated from these rgranules sincethey lack the degree of iexibility and compressibility necessary to theproduction of the cushion disks or seals `for bottle caps, particularlywhen gelatinous cements are used, notwithstanding that these cementsareof the nature of synthetic rubber. l L

With the harder lparticles of cork Wood there is apoorer bonding actionsecured with the cement used in making the composition cork, and a muchgreater tendency toward the disintegration of the composition cork as aresult of the action of liquids thereon when the caps are in posit-ionupon va bottle j containingsuch liquids.

`used in composition cork cushion disks forming a part of such caps,the'central portion ofthe exposed face of this cushion being providedwith a very thincoating of a highly This mate-- rial is ordinarilyproduced of what is known resilient substance so as toprotect the cementin the composition cork of the cushion disk from the contents of abott-le, the disk about this central portion having an uncoated p0rtionof suliicient width to -permit of the sealing of the neck of a bottle bya directcontact between same and this narrow strip of uncoatedcomposition cork adjacent the rim of the metallic shell. The material ofwhich this central facing is composed possesses considerable tenacity,is not responsive to changes in temperature or atmospheric conditions,and is suliiciently transparent and is applied in sufficiently thinstratum, to cause theentire exposedface of the composition cork disk tovary'so little as to make the presence of this coating non-apparent tothe causal observer. ,The material of the disk Will cement-itself iirmlyto the composition cork and Will not be alfected by the contents of abottle While effectively protecting the cement of the composition corkof the disk from the action of such contents.

By the method of my invention, the facing may be applied Withgreatrapidity to the cushion disks of bottle caps, and the area coatedwith the facing material, which when applied Y to the disk is in aviscous or semi-liquid form, Will be accurately defined as to the areacovered thereby, and this area will be practically the same as to alldisks.

In addition to thus facing the disk in the manner above described, I usea composition cork disk in WhichI rubber is-used as the cementingmedium, this rubber however, be-

ing incorporated in the mixture not as a liquid or semi-liquid cement,but in a manner Which will not only ensure a thorough application of therubber to the cork granules in the form of a superficial coating, butthe `Working of the cork in a manner which Will soften the harder corkgranules, and by possible breaking up of some of the cork granules causegreat homogeneity in the product.. vIt is immaterial .to the inventionWhether this cork composition becompressed into the cushion disksthereof. v

. The invention consists primarily in a bottle closure consisting of askirted metallic tubular rod form or in sheets before forming shell, aresilient sealiii said shell, and a thin lm of nitro-cellulose upon theexposed face of said disk, the edge of this film being concentric withthe skirt of said metallic shell, but spaced therefrom, whereby the neckof a bottle is sealed directly against the uncoated portion of saiddisk, and contact of the contents of a bottle with the composition corkof the disk is prevented; and in such other novel characteristics, andin the method of making s uch a closure, all as hereinafter set forthand described and more particularly pointed out in the claims heretoappended.

Referring to the drawings,

Fig. 1 is a sectional view, u on an enlarged scale, of a bottle closureem odying my invention;

Fig. 2 is a similar lview thereof upon a bottle; and

Fig. 3 is a diagrammatic view illustrating the method of applying thefacing film to the cushion disk.

Like letters refer to like parts throughout the several views.

In the embodiment of my invention shown in the drawings, a indicates askirted metallic shell such as is usually employed in bottle caps of thecrown type, and b a composition cork cushion disk positioned within theskirt of said shell and cemented to the inner top of the shell by astratum c of any desired or suitable cement, glue or adhesive. Upon theexposed face of the disk b is a thin film or coating d ofnitro-cellulose, the edge of this film bein concentric with the skirt ofsaid shell but eing spaced therefrom a distance to expose thecomposition cork throughout a sufficient area to ensure the lip of abottle sealing directly against same while causing the l'ilm ofnitro-cellulose to cover all portions of the disk b exposed to thecontents of a bottle. This nitro-cellulose will vof itself adhere rmlyto the material of the composition cork disk, is insoluble in thepresence of almost all beverages and will afford protection to thecement used in the composition cork to an extent to' avoiddisintegration of the disk even after long exposure to the contents of abottle. At the same time this coating while preventing contact of thecontents of the bottle with the cork or the cement, will preventcontamination of the contents of the bottle due to contact with the corkor the cement embodied in the cushion disk.

' The nitro-cellulose is in as thin a film as is feasible while stillsecuring a complete covering of the central ortion of the disk b,possesses sutlicient exibility to respond to the deformation of the diskresulting from the pressure exerted when applying a cap to afbottle, andwhen ina very thin ilm is almost transparent or at least highlytranslucent. When soused the entire exposed surface of the disk/hassubstantially the same disk secured within appearance. If, however, itbe desired to contrast the nitro-cellulose coating with the uncoatedportion of the disk, color pigment may be mixed with the nitro-celluloseto give any desired appearance to the coated portion of the disk.

While, by the method of making caps in accordance with my invention, thefilm of nitro-cellulose may be effectively applied to the compositioncork disk, irrespective of the quality of the cork in the granules, orof the binder used when binding these granules together, I preferablyuse a composition cork disk, the granules of which are bonded togetherby means of rubber as distinguished from a rubber or other cement. Inthe production of the composition cork from -which said disks are made,I thoroughly conimingle the cork granules with a vulcanizable rubbercompound using approximately parts of the granules of cork to one partof rubber by weight. 'Io facilitate the vulcanization of the rubber inthe subsequently compacted mass containing said granulated cork, I addan accelerator such as diphenol of granidine or formaldehyde to therubber compound. The cork is thoroughly mixed with the rubber compoundin an ordinary rubber milling machine.

The pressure exerted by the milling machine upon the mass of compositionbeing treated has the effect of repeatedly distorting the several corkgranules in a manner to have a softening action upon the cork, thussoftening the harder cork granules to an extent to permit theireffective use in the production of cushion disks for bottle caps. Thispressure will also tend to break the larger cork granules and securethat intimate relation between the rubber compound and both the largerand smallery cork granules, to ensure great homogeneity in disks madefrom the product of the milling machine.

The method of producing caps embodying my invention, permits theapplication of the facing iilm of nitro-cellulose to already assembledcaps or to such caps during the operation of assembling same. In otherwords, the method may be practiced in a machine, the sole function ofwhich is to apply this facing lilm, or an ordinary assembling machinemay have incorporated therein the necessary parts to apply the lm to thecomposition cork sealing disk during the assmbly of the cap. In eitherinstance the method will be the same and the product will be the same.

In the method of applying the facing film to the composition corkcushioning disk, I yfirst subject this disk adjacent the skirt of ametallic shell to a pressure suicient to compress the disk adjacent saidskirt and toward the center of the disk a distance coinciding with thearea of the disk which it is desired to have remain uncoated. This curedas a result of a single spraying action,

this lstep may be repeated.

The presser ring or annulus e will define the area upon Which thecollodion may be sprayedas described, the pressure exerted thereby uponthe cork preventing the extension of the coated area as a result of thediffusion of the collodion after it is applied in a sort of stipple. Theoutside diameter of the member e is substantially the same as the insidediameter of the skirt-of the shell a so that the facing film applied tothe space within the member e will be accurately centered, as to eachcap, with relation to the cushion' disk d. The pressure isA maintainedmomentarily after the collodion is sprayed upon the disk, to ,permitslight diusion thereof, and also to permit the setting of the collodiondue to the rapid evaporation of the ether and alcohol, or other solventfor the nitro-cellulose. If desired, heat may be applied to the capsduring the application of the collodion to the disk in order to expeditethe setting of the collodion..

So far as the application of the facing film is concerned, after thepressure from the presser ring or annulus is relieved, no subsequenttreatment is required, although the subsequent application of heat andpressure, or pressure alone to the otherwise completed cap, will notmodify the facing film in any t and thus will be firmly bonded to theVcomposition cork disk as the solvent for the nitrocellulose eva orates.By applying the collodion in a e spray, it will penetrate' the pores ofnatural cork and anchor itself firmly thereon. When applied in a verythin `film it will set with great rapidity, which setting `will be,accelerated by the lpresence of the compressed air, used in forming thespray.

. Furthermore by this method a very thin film of collodion may beapplied to the diskwith in the area defined bythe presser ring, thuspermitting the resulting film of nitro-celluloseto be very thin andhighly flexible. The use of a very thin film h'as the further advantagethat the solvent in the collodion Will evaporate very rapidly, thusmaking the time factor for applying the facing material so small as topermit a large production output. Furthermore the less the quantity ofthe collodion applied to the cushion disk of each cap, and the shorterthe time interval, the| more economical is the. production of such caps.

Heretofore I have produced caps having a facing disk of parchment paper,metal foil, or other like material, cemented firmly to the exposed faceof the cushion disk. Caps embodying my present invention, however,afford as effective a protection for the composition cork and for thecontents of a bottle as such other disks, and may be produced morevrapidly and at a much lower cost. Furthermore, in caps embodying mpresent invention there is no likelihood of a separation of the facingfilm from thev cushion disk, or a partial separation thereof.

By spraying the collodion upon the cushion disk, the entire portion ofthe disk within the pressure ring may be rapidly coated with a very thinfilm of collodion, which although applied in the yform of spray, willdiffuse, or flatten out, into a continuous film. The presser ring eforms a positive nbarrier preventing the extension of the coated portionof the disk beyond the area defined by said ring, the pressure beingrelieved before the collodion has completely set.

It is not my intention to limit the invention to the precise details ofconstruction herein described, nor to 'any particular time l "base, anda volatile solvent upon the exposed facel of a cushion disk while Withina metal shell.

2. The herein descbed method of making' bottle closures includng thestep of spraying collodion upon the ex sed face of a cushion disk Withina metal s ell.

3.- The herein described method of making bottle closures including thesteps of covering and compressing an annular portion of a resilientcushion disk adjacent the edge ythereof and spraying a eementitiousmaterial containing a water insoluble, inherently Hexible, base, and avolatile solvent upon the exposed face of the uncompacted portion of'said'disk.

4. The herein described method of making bottle closures including thesteps of covering and compressing an annular portion of a resilientcushion disk adjacent the edge thereof and spraying collodion upon theex posed face of the uncompacted portion of said disk. Y

5. The herein described method of making bottle closures includingtherein the stepspf comminuting a fluid eementitious material containinga water insoluble, inherently ilexible, base, and a volatile solvent-and depositing it upon the exposed face of a cushion disk within ametallic shell by means of a jet of air.

6a The herein described method of making bottle closures includingtherein the steps of comminuting collodion and depositing it upon theexposed face of a cushion disk Within a metallic shell by means of a jetof air.

7. The herein described method of making bottle closures includingtherein the steps of covering and compresslng an annular portion of aresilient cushion disk Within a metallic shell, adjacent the edgethereof, comminut` ing a fluid cementitious material'containing a waterinsoluble, inherently iexible, base, and a volatile solvent anddepositing it upon the exposed face of the uncompacted portion of thecushion disk by means ofa jet of air.

8. The herein described method of making bottle closures includingtherein the steps of coveringand compressing an annular portion of aresilient cushion disk Within a metallic shell, adjacent the edgethereof, comminuting collodion and depositing it upon the exposed faceof the uncompacted portion Vof the cushion disk by means of a jet ofair.

In Witness whereof I have hereunto affixed my signature, this 22ndl dayof June, 1925.

CHARLES E. MCMANUS.

